Henry malm



July 5,1927. Y 1,634,329

H. MALM PROPELLEH Filed April 24, 1926 f' 4; l0d Z x vENToR 'ITORNE`Patented `luly 5, 1927.

PATENTNVOFFICE.

HENRY Mania, or ivnwv YORK, N. Y.

PROPELLER.

Application led April 24, 1926. Serial No. 104,331.

This invention relates to propellers for marine or other uses comprisingtwo or more propeller blades extending radially from the axis or hubportion; and the object of the invention is to provide a device of theclass specified with means whereby the blaues of the propeller` may beadjustably supported in a hub or axis body whereby said blades may beadjusted to give different pitches thereto to adapt the propeller tomotors of different sizes or horse power or to variations in the powerof a given motor whereby the most en'icient results may be produced; astill further object being to provide a. propeller, the separate bladesof which are of similar construction permitting of the production of apropeller, the blades of which are truly balanced or of equal weight aswell as similar contour throughout; a still further object being toprovide a propeller construction wherein the separate blades may beremoved and new blades replaced or substituted therefor in the event ofbreakage or for other purposes, the adjustable coupling of the bla-deswith the hub portion being 4made by a dove-tailed and gear-like portionor portions interlocking with corresponding recesses or apertures in theseparate halves of said hub portion; and with these and other objects inview, the invention consists .in a device of the class and for thepurpose specified, which is simple in construction, efficient in use,and which is constructed as hereinafter described and claimed. Theinvention is fully disclosed in the following specification, of whichthe accompanying drawing forms a part, in which the separate parts of myimprovement are designated by suitable reference characters in` each ofthe views, and in which Fig. 1 isa face View of a propeller madeaccording to my invention.

Fig. 2 is a partial section on the line 2--2 of Fig. 1.

Fig. 3 is aface 'View of one part of the hub portion which I employ.

Fig. 4 is a detail view of one end of a propeller showing a modificationj and,

Figs. 5,- 6 and 7 are views similar to Fig. 4 but showing othermodifications.

In Fig.v 1 of the drawing, I have shown for the purpose of illustratingone method of carrying my invent-ion into effect, a propeller consistingof three blade members 10, of similar shape, tormenti constructionmounted in connection with a hub or axis portion or member 11, thelatter being composed of two substantially similar parts 11a and 11bcoupled together by a` number of screws 12 which in the constructionshown pass through the "part 11a and are in threaded engagement with thepart 11b.

All of the propeller blade members 10 are provided at their hub portionswith dove-tailed annular projections 13 which enter correspondingrecesses 14 in the parts 11L and 11b. At the end of the dove-tailedportions 13 are projectingand externally threaded annular members 15 toform substantial gear members thereof having radially projecting teethadapted to engage correspondingly formed recesses 16 in the separateparts 11a and 11b of the hub member 11.

It will be noted upon a consideration of Figs. 2 and 8 of the drawingthat the separate parts 11rL and 11b of the hub member 1l are providedwith flat outer faces 17 against which the shoulders 18 in the propellerblades 10 are adapted to rest whereby when the blades 10 are mounted inposition, the

`hub member 11 forms a substantial hub estension to said blades,resembling the natural appearances of a propeller having unitary hub andblade portions. It will be noted on a consideration of Fig. 3 of the ldrawing that the screws 12 pass through the separate parts 11el and 11bintermediate the recesses 14 and 16 and said parts having port-s orapertures 19 in which the shaft with which the propeller is adapted tobe coupled, is placed.

Vith the construction shown in Figs. 1 to Binclusive, it will beapparent that the dovetailed extensions 13 on the separate blade members10 serve to anchor said blade members within and to the hub member 11,and the gear portion 15 on said blade members .engaging the tooth-cutapertures or recesses 16 in the separate parts 11a and 11b, serves tointerlock and key the blade members 10 against rotationy in thehubmember 11.1

" In Fig. 4 of the drawing, I have shown a modification of theconstruction shown in Figs. 1`to 3 inclusive,'in which a part of ablade'member 10a similar to the'blade 10 is provided with aprojectingannular threaded or gear portion 2O next adjacent the blade and inwardlythereof with a projecting' anr nular dove-tailed portion 21. With thisconstruction, the diameter of the gear por-` tion 20 becomesflargey than.in the conv lli) jacent faces and arranged about the periphery of saidhub portion, dove-tailed recesses, and means for coupling said partstogether.

8. In a propeller, a hub portion divided transversely of the axisthereof to form two independent parts, said parts having on adjacentfaces and arranged about the periphery or' said hub portion, dove-tailedrecesses, means for coupling said parts together, and propeller bladeshaving dove-tailed Vprojections adapte'd to be mounted in the recessesof said parts and retained against displacementfrom said hub portionwhen the separate parts thereof are secured together.

9. In a propeller, a hub portion divided transverselyv of the axisthereof to form two independent parts, said parts having on adjacentfaces and arranged about the periphery of said hub portion, dove-tailedrecesses, means for coupling said parts together, propeller bladeshaving dove-tailed projections adapted to be mounted in the recesses ofsaid parts and retained against displacement from said hub portion whenthe separate parts thereof are secured together, and the recessedportions of said parts and the dove-tailed projections of the propellerblades having interlocking members to permit of rotary adjustment of theblades with reference to the hub portion and to retain said bladesagainstv rotary displacement with reference to the hub portion.

l0. In a propeller of the class described, a blade member, the hub endportion ot which is provided with a projecting part having a pluralityof radially directed and circum terentially spaced teeth, and saidprojecting part being dove-tailed in form whereby said blade may belocked against displacement from a hub portion, and said blade memberhaving a shoulder portion arranged adjacent the dove-tailed part andoutwardly thereof with reference to the hub portion ot the propeller.

In testimony that I claim the Jforegoingas my invention I have signed myname this 21st day of April, 1926.

HENRY MALM.

